Typische Software Fehler Dichte

How buggy — or risky — is Operating Systems Software?

In 1998, a Microsoft website claimed NT5 would fix more than 10.000 outstanding bugs in NT4. Hence, quite obviously, NT4 contained more than 10.000 serious bugs.

According to a Microsoft-internal memo leaked to the press at the time when Win2000 was released,
Microsoft's Prefix tool discovered that the final Win2000 release code still had more than 63,000 "potential issues" that could emerge as problems.

Microsoft estimated that 28.000 of these were likely to be "real" problems.

It is well known that Win95 code was around 10 Mio Lines of Code (LOC), so if we assume that Win2000 had around 28 Mio LOC, there was likely to be one problem per 1000 LOC in Win2000.

Despite of this — as we all know — Win2000 was a very usable software package.

On the other hand, most simple bugs can create a lot of damage:
Because of "a misplaced decimal point" in the code for the delivery system of the Titan IV rocket, the U.S. Government lost two of these quite expensive rockets.
Without them the military could not deploy early warning satellites.